Modeling of perforated plates and screens using rigid frame porous models

Atalla, Noureddine; Sgard, Franck

doi:10.1016/j.jsv.2007.01.012

Cited by 189 publications

(199 citation statements)

References 7 publications

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“…13 Surface acoustic impedance of the PP was obtained by the Atalla and Sgard model. 14 The acoustic-transmission approach (ATA) approach was used to estimate the surface impedance of consecutive layers. 7 Finally, different combinations of multilayer structures with multiple PP, coir fiber, and air gap were analyzed by means of these calculation procedures.…”

Section: Methodsmentioning

confidence: 99%

“…14 In the case of perforated panel backed by a cavity, total input impedance of the perforated-air layer combination is expressed as…”

Section: Atalla and Sgard Model For Pp Modelingmentioning

confidence: 99%

“…(8) based on the material, and φ is the porosity of the porous layer backed by PP. 14 The ATA method was applied, accompanied by the Atalla and Sgard model to obtain surface acoustic impedance of various consecutives layers together. 7,14 Using the ATA technique, the surface acoustic impedance Γ j of the jth layer is represented by Eq.…”

Section: Atalla and Sgard Model For Pp Modelingmentioning

confidence: 99%

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Analysis on Multiple Perforated Plate Sound Absorber Made of Coir Fiber

Ayub¹,

Fouladi²,

Ghassem³

et al. 2014

IJAV

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Current studies are aiming to improve the sound absorption of coir fiber by implementing combinations of Perforated Plates (PPs) and air gaps. The Atalla and Sgrad model along with Johnson-Allard model and Acoustic Transmission Analysis (ATA) approach are used to estimate the absorption coefficient of the combination. Measurements are conducted in impedance tube to validate the analytical results. Outcomes show that the absorption coefficient of the panel is governed by the porosities of the implemented PPs. Reduction in the porosity of the face PP causes the incident sound to reflect back whereas higher porosity encourages the sound to enter and be absorbed gradually in the inner compartments. For the case of multilayer panels with two PPs, the best result is obtained when the inner PP has low porosity and is backed with an air gap. Absorption in high and low frequency bands are enhanced by having highly porous material and a thick layer of air gap in front of and behind the inner PP, respectively. This study shows that the high-frequency absorption is enhanced further in panels that include three PP layers. The study suggests fabricating panels containing two or three PPs with gradual reduction of porosity from the face PP to the inner ones, while the inner most PP has low porosity and is backed with air gap.

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Section: Methodsmentioning

confidence: 99%

“…14 In the case of perforated panel backed by a cavity, total input impedance of the perforated-air layer combination is expressed as…”

Section: Atalla and Sgard Model For Pp Modelingmentioning

confidence: 99%

Section: Atalla and Sgard Model For Pp Modelingmentioning

confidence: 99%

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Analysis on Multiple Perforated Plate Sound Absorber Made of Coir Fiber

Ayub¹,

Fouladi²,

Ghassem³

et al. 2014

IJAV

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“…This correction is based on the radiation of infinitely baffled circular piston. Note that more advanced correction terms were also proposed recently in [33]. In as econd model, the internal porosity of the panel and the additional dissipative effects resulting from the coupling between the micro-scale of porosity and the scale of the perforations are accounted for.T he method used here is the analytic approach based on the theory presented in [1].…”

Section: Modeling Of the Multi-layer Systemsmentioning

confidence: 99%

Applications of the Dual Porosity Theory to Irregularly Shaped Porous Materials

Bécot¹,

Jaouen²,

Gourdon³

2008

Acta Acustica united with Acustica

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SummaryNon planar acoustic materials may be used in building and environmental acoustics to achieve asignificant absorption at lowfrequencies. Examples of these materials are anechoic wedges or advanced design noise barriers. The shape of these materials is mainly based on empirical knowledge because afi ne numerical modeling (e.g. FEM, BEM)r equires large computational costs. Therefore, the optimisation of the general form and of the material used to realise these absorbing systems is limited. The purpose of this paper is to propose an original alternative to these limitations. The work basis relies on the theory for the acoustics of multi-scale porous materials, and in particular on double porosity materials, which has been initiated by Olnyand Boutin (J. Acoust. Soc. Am. 2003, 114(1)). It is shown in this paper that this theory could be successfully applied to the modeling of non planar sound absorbing materials. Examples are givenfor multi-layer systems involving perforated panels, material samples having an irregular surface and anechoic wedges. The discussion is based on comparisons between analytical simulations and measurements.

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“…Although typically studied configurations consist of a flat rigid surface with periodically arranged circular holes or slits, some authors have proposed ways to model different perforation shapes or non-traditional designs of the perforated panel [6,7]. Atalla and Sgard [8] have shown that a perforated plate or screen can be modeled as an equivalent fluid following the Johnson-ChampouxAllard approach [9,10,11] with an equivalent tortuosity and that those classical models can be reobtained by using this simple approach. Even though most of these models have been experimentally validated through the years, some uncertainties related to more complex configurations arise.…”

Section: Introductionmentioning

confidence: 99%